Alright this is my 2nd post regarding about the pooping incident, I posted a thread earlier on about it not pooping for 1 week but now 2 weeks? i've tried 3 days fasting and 1 day per week fasting as well.. i reduced his feeding to 3-4 pellets per day. any tips? he looks fine as well.. i'll put a photo

Housing
What size is your tank? 2.8 Gallons
What temperature is your tank? 81 degrees
Does your tank have a filter? no
Does your tank have an air stone or other type of aeration? no
Is your tank heated? yes
What tank mates does your betta fish live with? no one

Food
What type of food do you feed your betta fish? pellets (Hikari)
How often do you feed your betta fish? 3 pellets x 2 times per day

Maintenance
How often do you perform a water change? 100% once a week
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? ammonia and chlorine neutralizer

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Symptoms and Treatment
How has your betta fish's appearance changed? his fine, acting normal and is active
How has your betta fish's behavior changed? he used to poop once a week and the size of the poop is large.. but now 2 weeks and nothing
When did you start noticing the symptoms? last week
Have you started treating your fish? If so, how? Yes, I fast my fish for 3 days now and 1 day per week
Does your fish have any history of being ill? he had fungus but healed and tail was damaged when bought, now its grown back :D
How old is your fish (approximately)? 7 months old

IDK about the rest, but 3 pellets twice a day is too much. Only feed a max of four pellets a day, maybe 5 if they're smaller. Also, you need to do 2 water changes a week, 1-50% and 1-100% in your size tank :)

Alright this is my 2nd post regarding about the pooping incident, I posted a thread earlier on about it not pooping for 1 week but now 2 weeks? i've tried 3 days fasting and 1 day per week fasting as well.. i reduced his feeding to 3-4 pellets per day. any tips? he looks fine as well.. i'll put a photo

Housing
What size is your tank? 2.8 Gallons
What temperature is your tank? 81 degrees
Does your tank have a filter? no
Does your tank have an air stone or other type of aeration? no
Is your tank heated? yes
What tank mates does your betta fish live with? no one

Food
What type of food do you feed your betta fish? pellets (Hikari)I suggest getting a different brand. The hikari isn't good for bettas.
How often do you feed your betta fish? 3 pellets x 2 times per dayI would lessen it to two pellets twice a day.

Maintenance
How often do you perform a water change? 100% once a weekThis is too little. At minimum you should be doing one 50% and one 100% a week. Increase the amount of changes while he is still sick
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? ammonia and chlorine neutralizer

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Symptoms and Treatment
How has your betta fish's appearance changed? his fine, acting normal and is active
How has your betta fish's behavior changed? he used to poop once a week and the size of the poop is large.. but now 2 weeks and nothingFish should poop more than once a week.
When did you start noticing the symptoms? last week
Have you started treating your fish? If so, how? Yes, I fast my fish for 3 days now and 1 day per week
Does your fish have any history of being ill? he had fungus but healed and tail was damaged when bought, now its grown back :D
How old is your fish (approximately)? 7 months old

I would just start with more water changes. Try giving him some daphnia, it will help will the constipation.

When I got my fish, his cup water was crystal clear, he was kind of bent to one side, was very skinny, (I know now) and had NO self control eating. He was willing to take a pellet from me almost as soon as I got him in his bowl. (until his aquarium was done cycling.) Turns out he was constipated. I was afraid to use epsom salts, or to give him a bit of pea since it had mixed reviews on it working. I ended up getting freeze dried gammarus. (I couldn't find freeze dried brine shrimp or daphnia) I gave him half of one crumbled up and he pooped within a couple hours. The little jar of it said it "supports digestion"

I don't know if it was a coincidence or not, but it seemed to work in my case.